This invention relates to management of large files in an object management system. Existing systems, such as those used with Oracle databases, are designed to handle extremely large tablespaces. A tablespace may be made up of a plurality of data files, which are files that may be accessed or manipulated by an operating system. “Data file” refers to a file that can be copied, moved, or otherwise treated as contiguous information, regardless of whether the data is physically stored in a contiguous manner on the storage media.
Local storage capacity may not be sufficient to store an entire tablespace associated with one or more databases. It may be uneconomical to purchase sufficient fast access storage media (such as hard disks or optical media) to provide enough capacity to store an entire database, particularly when not all of the data need necessarily be accessible at relatively fast speeds. Conventional database systems have been implemented in which data may be “migrated” to less expensive media and retrieved from the media only when required. However, existing systems and methods do not efficiently manage data to be migrated, after migration, and after retrieval. These systems suffer from latency, have high bandwidth requirements, require long backup times, have high costs, and may not be capable of making “point in time” snapshots. These problems are not limited to databases and tablespaces. Rather, they may apply to systems that store large files, such as multimedia.
A more effective approach, as will be disclosed herein, would reduce the latency and bandwidth requirements, reduce cost, and require a smaller backup window, thus managing the data more efficiently. Although the disclosure herein may describe the problem and the invention in the context of databases and tablespaces, the invention may be applied to any data management system using migration, particularly when the system manages large data files such as audio or video.